fix: allow dist2wheel to handle missing field

Allow `dist2wheel.py` to better handle missing extra field
on the internal goreleaser build artifact.

Fixes: #193

python/dist2wheel.py

@@ -66,7 +66,7 @@ def create_all(self):
 
         # Burn a pass through the list to steal some useful bits from the Brew config
         for artifact in self.artifacts:
-            if "BrewConfig" in artifact["extra"]:
+            if artifact["type"] == "Brew Tap":
                 self.description = artifact["extra"]["BrewConfig"]["description"]
                 self.license = artifact["extra"]["BrewConfig"]["license"]